On-Site Sewage Facilities

Development Services | 211 Jackson Street | Bastrop, Texas 78602 | (512) 581-7176




Bastrop County On-Site Sewage Facilities Order


Bastrop County is the "authorized" agent for the Texas Commission for Environmental Quality (TCEQ).  Bastrop County has adopted the TCEQ rules from Title 30 Texas Administrative Code Chapter 285.  Bastrop County has adopted more stringent rules in the Bastrop County On-Site Sewage Facilities Order to include:

  • All septic installation/modifications require a permit, regardless of acreage.
  • All structures to be used as a residence are required to obtain an OSSF permit to assure compliance with the order.
  • Homeowners may maintain their own aerobic systems after the initial 2 year mandatory maintenance contract with a Licensed Maintenance Provider with approved training.
  • The minimum sizing factor for any structure up to 1,500 square feet is 180 gallons per day, including guest houses, workshops, detached garages, recreational vehicles (RV's), etc. with the exception of RV parks.  RV parks are defined in the order as 5 or more RV's on one tract of land and they may be designed for 50 gallons per day.  (Note that the Bastrop County Infrastructure Requirements for Lodging & Recreational Vehicle Park Developments define an RV park differently.)
  • All proposed and existing structures shall be included on the septic design, including secondary residences, guest houses, septic systems, outbuildings, barns, sheds, etc.  Water lines, water meters, water wells, overhead electric lines, driveways and access easements must also be shown.
  • Surface irrigation systems shall not be designed with overlapping spray patterns.
  • If a system is being designed for more than one occupied structure, there must a minimum 750 gallon septic tank for each home preceding the required treatment and disposal components.

With few exceptions, a permit is required to construct, install, alter, extend, or repair an On-site Sewage Facility (OSSF).  Since local permitting programs can be more stringent than the state law, always check with the Bastrop County Environmental & Sanitation Services Department.   

A permit is not required for emergency repairs (replacing tank lids, inlet and outlet devices, and repair of solid lines), but they must be reported to this office within 72 hours after repairs have begun. Emergency repairs are defined in 30 TAC Subchapter D, 285.35.  

A list of TCEQ Licensed OSSF Professionals can be obtained at the link https://www2.tceq.texas.gov/lic_dpa/index.cfm?fuseaction=licall.searchgp.   Enter OSSF, Bastrop County and Zip Code 78602 into the search fields, and click "Search" at the bottom of the page.

Frequently Asked Questions

  • As long as the permitting process is followed and a "Permit to Construct" is issued, the owner of the property may install the septic system if the development is a single family residence that he/she will inhabit.  All OSSF planning materials are required to have a Site Evaluation Report prepared by a Licensed Site Evaluator or a Professional Engineer.  Any person hired to install a septic system must be a Licensed Installer.
  • Ask your Site Evaluator about your options.  The type of system is chosen based on the type of soil on the property.  If the Site Evaluator determines that there are Class lB, Class ll or Class III soils to at least 42 inches below the surface, with no restrictive subsurface horizons and no restrictive surface features, any type of system is usually an option.  If there are Class lA or Class IV soils, restrictive horizons or any other restrictive site features, options may be limited.  
  • The term of the Permit to Construct is one year.  This means one year is given to have the system installed, inspected and receive final approval.  The License to Operate is the notice of approval that lasts for the life of the system until there is a modification or significant change in the water usage.
  • No.  First, you must own a legal tract of land consistent with state law and Bastrop County Subdivision Regulations.  The proposed location of the septic system must meet TCEQ and Bastrop County minimum separation distances (setbacks) from property lines, water wells, buildings, easements, bodies of water, etc.  Other restrictions may also apply to property wholly or partially within regulated floodplain.  A site plan showing the proposed location of any structures, driveway and the septic system must be submitted with the permit application.
  • Current TCEQ rules require the following:

    Platted or unplatted subdivisions of single family dwellings served by a public water supply and using individual OSSFs for sewage disposal, shall have lots of at least 1/2 acre.

    Platted or unplatted subdivisions not served by a public water system and using individual OSSFs, shall have lots of at least one acre. 

    A lot must be large enough to allow the septic system to meet all the required setbacks based on the size of the system.  For small lots, less than 1/2 acre, the system must be designed by a Registered Sanitarian or Professional Engineer, regardless of the system type.

  • A mandatory two year initial maintenance contract with a Licensed Maintenance Provider is required with the installation of a new aerobic OSSF system.  Maintenance of an aerobic system is required for the life of the system.  Two years after the initial installation of your aerobic treatment unit, maintenance can be performed by homeowners for systems that use secondary treatment systems, non-standard treatment systems, drip irrigation, and surface application disposal.  Bastrop County does require homeowner training for those homeowners desiring to perform their own maintenance.  Alternatively, a maintenance contract can be obtained through a Licensed Maintenance Provider.